Here are a couple of grenades for dispersal of "Tear Gas" used in crowd control. Two different delivery systems.

The M47 is made of two rubber hemispheres vulcanized
together. This vents gas from a small hole.
The M227 igniter has a dual safety feature, with a 2.5 -3.5 second
delay.

The M25 is constructed of a phenolic material.
This is a bursting type.
The fuze (C12) is integral to the grenade and has a 1.5 to 3 second delay.

The M47 uses a CS pyrotechnic filler. It is a granular solid, which burns internally
and produces a high pressure gas jet, which vents out a small port. This
is designed to spin the grenade in an erratic manner across the ground. It
burns for about 5 to 25 seconds.
The gas is a powerful lachrymator which takes effect in about 15 seconds and lasts 30 minutes to several hours.

The M25
is filled with CN-1. The busting charge scatters pulverized agent in a
large cloud over a 5 meter radius. CN is not as potent as CS. It takes effect
in about 15 seconds but only lasts about 5 to 20 minutes.
This grenade is unmarked
which may mean it is Canadian issue.

About Markings:
The "X" prefix indicates the grenade was issued while still in the trial
stages. The following "E" denotes the variation of the design. So "XM47E3"
means this is the third variation of the trial grenade M47. (Earlier marking nomencature used a "T" instead of the "X".)
The "A" following the M25 is a variation designation for grenades already adopted for use.

The M47 safety lever has a secondary thumb release. It needs to be slid back after the pin is removed.
On the bottom in a large fill plug. The vent port is covered by black tape, which is removed prior to use.

The fuze for the M25 is similar in function as the WWII RussianKoveshnikov fuze.
The spring loaded center slider tube is held in a cocked position by two locking
balls. In turn they are held by a spring loaded arming cap.
The thrower put their thumb on the arming cap, pulled the pin and
threw the grenade. The arming spring pushes the cap off, freeing the balls allowing the slider tube to be forced down.
In this fuze, the busting charge is contained in the slider, with the primer
exposed at the bottom. The threaded base plug functions as the firing pin.